Stealing an iPhone

November 30, 2010 BY danariely

Here is a letter I got last week:

Dear Professor Ariely,

I have something of a story that intrigued me along the lines of your ‘dishonesty’ experiments. My wife’s cousin (I’ll call her Mary) is generally a nice, honest person. She and her fiancé found an iPhone on vacation. They decided to keep the phone, a nice item of value. Soon after, the owner started calling repeatedly (his name comes up on the screen). Mary chose to not answer the phone. After many calls were unanswered, the calls stopped. Mary kept the phone.

Mary’s situation is special because it is an instance where the lost object can ‘communicate’ with the finder and ‘ask’ to be returned. To what extent and to how long would the average person wait before answering? Would they directly refuse to return the item, or demand compensation?

What if you could rig a phone to deliver a series of text messages that become increasingly personal? Would the finder then feel more connected to the owner, feel empathy, and be more likely to return the phone?

As a side note, the owner of the iPhone was able to remotely shut down the phone so nobody could benefit. The unfortunate outcome is a lost phone. The upside is the empowerment given to the owner, who as a last resort just stops the functionality.

What do you think?



Dear Jack,

I think that there are two very interesting points here:

The first is that Mary probably realized that if she answered the phone she would feel obligated to return the iPhone to its owner. And since she did not want to give it up, she simply did not answer the phone. This act is in essence a very sad type of self-control.  Generally we try to exert self-control when we want to assure that we will behave well (save money, take medications, not procrastinate), but here Mary was trying to avoid the temptation that would have made her behave in a kind way.

The second interesting idea is that people are more likely to return items that are more personal. Text messages are one extreme example of this principle, but maybe it would also work for wallets with pictures, books with names, cloths with initials, etc.

Not sure if this helps, but maybe we could learn something from Mary’s behavior.  And for sure don’t leave any valuables unattended during thanksgiving.

Irrationally yours


Helping kids raise $

November 25, 2010 BY danariely

Here is a letter I got from Mary Kate Dilworth ….

Dear Dan,
Hello.  My name is Mary Kate Dilworth, and I am a junior at Thomas Jefferson High School for Science and Technology in Alexandria, Virginia. Last summer, I read a copy of Predictably Irrational, and now it sits on my bedside table because I reference it so often in my life.  I find the chapter on social v. market norms particularly applicable to my life (I am in several volunteer organizations that regularly do fundraising projects).

Today, for example, my school’s Russian Honors Society had an Election Day bake sale.  In years past, various goods have had set prices, but this year we chose to make it donation-based.  What a difference it made!  When one woman bought a cupcake, she reached for a one dollar bill and asked about the price.  When I told her there was no set price but donations-only, she put the one back in her wallet and pulled out a ten.  Your suggestion to switch to social instead of market norms was a great one-thank you so much!

Mary Kate Dilworth


Dear Mary Kate,

This is great, and I am delighted that you are taking lessons from the book and implementing them.

Next time think about trying both versions and measuring more directly the difference.  It would be interesting to know if the effect is driven by a few people who give much more, by many people who give a bit more, or perhaps by more people becoming interested in the bake sale (or maybe all of these).

And good luck in your next implementation.